ENCAPSULATION is the grouping of data items and functions into a type. By this we mean, if you have operations you want to perform on a student, you would sum them up, both the properties of the student and the operations you want to perform on them and encapsulate them into a class.

So we would have the class student that can contain properties like

i. Name
ii. Age etc.

And also operations like

i. AssignStudentID
ii. ChangeDepartment etc.

This would make it more organized and resuable.

That's the advantage of encapsulation.

Abstraction - It is the view of an object in context. For you to be performing an abstraction, you have to take a real world object and consider the properties of that object that are of use to your application.

EXAMPLE

If you have to make and abstraction while trying to write a software for calculating results at a university, properties of a person that would be of intrest to you would inculde:

i. Age
ii. Gender
iii. Program of study

You wouldn't be too interested in the persons relationship status.

This is because you are only concerned with things about the person that would enable you develop a working application. You are trying to view the person "in context".

1. Dynamic RAM has to be constantly refreshed while static RAM doesn't.
2. Dynamic RAM is cheaper than static RAM.
3. Dynamic RAM is slower than static RAM.

IRQ is short for Interupt ReQuest. It's a signal that hardware devices generate to interupt the current operation of the CPU. It allows the CPU to pause and decide what to do next. It allows the PC to be able to respond to addition of new hardware. 

Take for example, a PC has tasks queued up that would take an hour to process. If there are no interupts, the PC would have to finish its current tasks before it gets to the task that the hardware added and process it. That is going to be very inefficient. 

That's thats why interupts are important. They enable the processor give time to the hardware if its priority is higher than the current tasks its handling.

Think also of your mouse, if you have ever been on a slow PC you would realize that sometimes everything but the mouse can be hanging. 

Thats because the mouse hardware generates an IRQ and its got a higher priority the processor processes its requests before going back to the requests that caused it to hang.

REFERENCE
http://www.computerhope.com/jargon/i/irq.htm

 div ~ p (all P's in the same hierarchy as div)
div + p (p immediately after div)
div > p (p contained directly under div, there must be no tag in between)
div p (p contained under div even if there's another tag in-between them)

 p::before{
    content: " adds the content here before the p element";
}
p::after {
    content: "adds the content here after the p element";
}

---

div {
    box-shadow: 10px 20px #888888;
   <!-- 
The 10px represents left offset
The 20px represents top offset
}

---

NOTE: The tags used in the examples can be substituted with any valid html tag.

Sick of browsing with half your screen?

Well then take out the toolbars. Here's how to do it:

Step 1 - Click on the highlighted button and then click addons

Step 2 - Click on extensions then click the remove button beside all the stuff there that you didn't download yourself.

Most of you would have noticed that the experience index isn't in windows 8.1 anymore.

WHAT IS EXPERIENCE INDEX?

 Windows experience index is a means of benchmarking or comparing windows systems. It rates the hardware available to a pc and gives a number to enable you compare with friends and know whose pc is more superior.

It used to look like this:

But on windows 8.1 its not there anymore.

The only way it can be accessed is through the CLI (Command Line Interface).

To do view it follow these steps:

Step 1: type cmd in the start menu and press enter.
Step 2: type "winsat prepop" in the window that appears

Step 3: type "windows powershell" in the windows start menu and press enter.

Step 4: type "Get-WmiObject -Class Win32_WinSAT" in the window that opens

Step 4: View results.

The "WinSPRLevel" is your summary score and the remaining scores are individual scores in different categories like memory, 3d graphics, etc.

Your summary score is always the lowset score you get in each individual category.
You can now compare this score with friends.

Hope this helps!